The present invention relates to hanger devices with self-locking jaws, for example used as wall hangers enabling an object to be held vertically.
A hanger device of this kind can comprise a base and at least a couple of two jaw blocks mounted rotating on the base according to two parallel axes, with means setting the clearance distance between the jaw blocks and the base. The jaw blocks of the couple of jaw blocks are symmetrical to one another with respect to the transverse mid-plane which separates them, and have eccentric curved bearing faces extending between a first end situated away from the axis and a second end close to the axis. The jaw blocks pivot around their respective axes between a clamping position in which the first respective end portions of bearing faces are facing one another, close to one another or pressing against one another, and a released position in which the second respective end portions of bearing faces are facing one another to leave a free space between the two jaw blocks. The object to be hung is engaged in an upward direction between the two jaws, separating the latter, after which the weight of the object tends to make the two jaws pivot in the direction of their moving towards one another, the two jaws then clamping the object on both sides and preventing it from falling.
In simple structures, described in CH-A-113,521, CH-A-193,030 or CH-A-235,542, the jaw blocks are not synchronized and pivot independently from one another.
An improvement consists in providing a synchronizing device which performs synchronization of the jaw blocks of the couple of jaw blocks according to reverse rotations around their respective axes. In this case the jaw blocks can be made of different materials and be given complex shapes, at the same time achieving the synchronizing device. But a relatively complex device then has to be produced in which the synchronizing device may sometimes bind or seize due to dust or grains of sand getting inside, so that such a device is relatively fragile and does not present the reliability required for use without precautions. This is the case, for example, in the structures with cog-wheels described in FR-A-321,861 or in DE-A-3,818,031.